这道题我没有答案, 帮忙确认一下?

maggiecookies

T-4-Q33

In attempting to solve the problems caused by a lowering of the price of oil, oil companies operating in the North Sea have taken a variety of approaches, which includes their reducing employment, using new technology to pump oil more efficiently from smaller fields, and finding innovative way to cut the cost of building and operating platforms.

1. which includes their reducing employment, using new technology to pump oil more efficiently

2. which includes reducing employment, using new technology to be more efficient in pumping oil

3. which include reducing employment, using new technology to pump oil more efficiently

4. which include the reduction of employment, their using new technology to pump oil more efficient

5. including a reduction of employment, their use of new technology to be more efficient at pumping oil

我选B, 对吗?

VicSi

偶选Ｃ　

include 用复数瓦